It's worth mentioning that it's not really recommended to try calling usbd_poll from the irq handler, as it ends up with all the user callbacks running in interrupt context.
Dave Hylands <dhyla...@gmail.com> wrote: > I did a version for the STM32F4 which you can find here: > https://github.com/dhylands/libopencm3-usb-serial/blob/master/usb-serial.c > > I set things up to call usbd_poll from the isr handler: > https://github.com/dhylands/libopencm3-usb-serial/blob/master/usb.c#L290-L295 > > and then uses the SOF handler to transfer bytes into a circular > buffer. > > > On Thu, Mar 2, 2017 at 3:00 PM, kristoff <krist...@skypro.be> > wrote: > > > Hi, > > > > > > Can somebody explain how to really use the CDC ACM (serial over usb) on > > a STM32F1? > > > > > > In libopencm3-examples, there is an example on using cdc acm > > (serial-over-usb), however I cannot modify the example to do something > > usefull. > > > > The example only sets up the cdcacm-device and then does two things: > > - there is an endless loop that just does usbd_poll > > - inside the callback function, there is some code that echoes the > > characters it received back to the usb-device. > > > > > > But how do you write an application that actually does something usefull? > > When I modify the "usbd_poll" loop to actually does something (like just > > print out a line "count = ...", this results in errors when I boot the > > device (i.e. "Device not responding to setup address."). > > > > So it looks like you really need to have this continues-cycle of the > > usbd_poll running. > > > > > > So how I you actually make an application that uses that cdcacm > > interface and make it actually do something usefull? > > > > > > > > Cheerio! Kr. Bonne. > > > > > > ------------------------------------------------------------ > > ------------------ > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > > _______________________________________________ > > libopencm3-devel mailing list > > libopencm3-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/libopencm3-devel > > > > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! > http://sdm.link/slashdot_______________________________________________ > libopencm3-devel mailing list > libopencm3-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/libopencm3-devel
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